Silicate Mineral (Tectosilicate)

Scapolite

The Shaft Stone

Purple-Violet
Golden Yellow
Pink
Colorless

Quick Facts

FormulaNa₄Al₃Si₉O₂₄Cl – Ca₄Al₆Si₆O₂₄CO₃ (solid solution)
SystemTetragonal
LusterVitreous
StreakWhite
TransparencyTransparent to Translucent
Sp. Gravity2.55-2.74
Mohs Hardness
6

Formation & Origin

Scapolite (from the Greek 'skapos' meaning shaft or stick, referring to its prismatic crystal habit) is actually a solid solution series between two end members: marialite (sodium-rich) and meionite (calcium-rich). Most specimens fall between these extremes.

It forms in metamorphic rocks, particularly in skarns (contact-metamorphosed limestones), amphibolites, and granulites. In these environments, scapolite replaces plagioclase feldspar through a process called scapolitization, where chlorine and carbon dioxide-bearing fluids alter the original feldspar.

Gem-quality scapolite comes in attractive purple, golden yellow, and pink varieties. Purple specimens can resemble amethyst, and yellow stones can look like golden beryl. Cat's-eye scapolite (showing chatoyancy from needle inclusions) is particularly sought-after.

Identification Guide

Scapolite is identified by its tetragonal prismatic crystal habit (long, square-cross-section columns), moderate hardness (6), and vitreous luster. RI of 1.536-1.600 and biaxial optic sign help separate it from similar-looking gems.

Distinguish from amethyst (trigonal, different RI for purple varieties), golden beryl (hexagonal, different RI for yellow varieties), and topaz (orthorhombic, higher RI). The tetragonal crystal system and specific RI range are diagnostic.

Spotting Fakes

Scapolite is not well-known enough to be commonly faked. The main confusion is with more familiar gems of similar color: purple scapolite for amethyst, yellow scapolite for citrine, and pink scapolite for morganite. RI measurements distinguish between these. Cat's-eye scapolite is distinctive enough to be less commonly confused.

Cultural & Metaphysical Traditions

Presented as cultural traditions, not scientific evidence

Scapolite is associated with problem-solving, independence, and breaking free from self-imposed limitations. Its columnar crystal habit connects it to themes of direction and reaching for goals. The replacement of feldspar by scapolite in nature is interpreted as a metaphor for transformation and upgrades in personal development.

Where It's Found

Tanzania - Umba Valley, Morogoro

Fine purple and yellow gem material

Myanmar - Mogok

Pink and violet crystals

Brazil - Bahia

Large yellow crystals

Canada - Quebec, Ontario

Large crystal specimens

Price Guide

Entry$10-40/ct common quality
Mid-Range$40-200/ct fine purple or yellow
Collector$100-500/ct cat's-eye specimens

Good to Know

💎

Scratch test: At hardness 6, Scapolite resists scratching from a knife but can be scratched by quartz. Best for pendants and earrings rather than rings.

🌍

Sources: Found in 4 notable locations worldwide, from Tanzania to Canada.

⚖️

Heft test: Scapolite has average mineral density (2.55-2.74). It feels about as heavy as you'd expect from a stone its size.

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